Interest is increasing in street-level research personnel, whom we call "research extenders" (REs), employed by researchers because they share characteristics (geographic, ethnic, and/or personal experience with the focal research problem) with the targeted research population, and thus can be effective, or even essential in recruiting and developing rapport with research subjects. However, these similarities may also raise issues in human subjects protections, including social risk for research participants, difficulty in maintaining confidentiality, and challenges to appropriate boundaries in research relationships, which may compromise the validity of the data. Using primarily qualitative methods (in-depth interviews,,scenarios, focus groups), the goal of this study is to generate knowledge about the understandings of this understudied segment of the research community related to the responsible conduct of research, leading to more targeted and nuanced training approaches for them, and in turn, enhancing research integrity and promoting collection of valid data in vulnerable populations. AIM 1) Using in-depth interviews with 2 types of REs: those who only perform research activities (single role REs) and those who combine research activities with service provision (dual role REs), we examine how both types of REs understand and approach responsible conduct of research. H1a: REs will identify and discuss ethical conduct in ways that differ from the standard framework, provided by guidance documents such as the Belmont Report. H1b: Dual role REs will identify and discuss some ethical conflicts that are not identified and discussed by single role REs. AIM 2: To discover factors, identified by both types of REs and their supervisors as facilitating or impeding the ethical conduct of research. Separate focus groups, conducted with single role REs, dual role REs, and their supervisors, will explore effectiveness of existing formal and informal training, difficult encounters for REs and supervisors to manage; and supervisor confidence about data validity and strategies used if validity is questioned.